The Stages of Neuroblastoma
The treatment a child receives for neuroblastoma depends on the risk group assigned. Risk is determined by age, tumor characteristics (pathology and genetics), and stage--the extent to which the disease has spread. Disease stage is determined according to the International Neuroblastoma Staging System (INSS), developed in 1988 and last revised in 1993. The staging system is currently under revision by the International Neuroblastoma Risk Group (INRG) task force. The diagnostic tests listed above help doctors assign the child's disease to one of the following INSS stages (percentages of each stage are taken from North America data on 1253 neuroblastoma cases):
Stage 1 - 21%
The tumor is confined to one area of origin and can be completely removed through surgery. Although microscopic residual disease may remain after surgery, identifiable lymph nodes on both sides of the body are negative for neuroblastoma.
Stage 2 - 15%
2A - The tumor is confined to one area but because of size, location, or proximity to other organs, cannot be completely removed. Identifiable lymph nodes on both sides of the body are negative for neuroblastoma.
2B - The tumor is confined to one area and may or may not be completely removed. Identifiable lymph nodes on the side of the body where the tumor is located are positive for neuroblastoma, but lymph nodes on the opposite side of the body are negative for neuroblastoma.
Stage 3 - 17%
The tumor crosses the midline of the body (defined as the spine) and may or may not have spread to nearby lymph nodes; OR
the tumor is confined to one area of the body with disease in lymph nodes on the other side of the body; OR
the tumor is located crosses the midline with disease in lymph nodes on both sides of the body
Stage 4 - 41%
Neuroblastoma is found in distant lymph nodes, bone marrow, bone, liver, or other organs (except in the special circumstances of Stage 4S, explained below). Indication of presence of neuroblastoma cells by immunocytology alone (no visible tumor cells in bone marrow biopsy or aspirate) does not classify a child as stage 4.
Stage 4S - 6%
Usually in infants, the tumor is confined to one area of the body, like a Stage 1 or 2 tumor, but disease has spread to only the liver, skin, or less than 10 percent of the bone marrow (no bone lesions).